There are 2468 rhymes in metrical poems and 24 rhymes in quatrains. Whether it is a metrical poem or a quatrain, the first sentence may or may not rhyme.
Step 2 lower the rhyme
In order to harmonize the sound and rhyme, modern poetry generally balances the sound and rhyme, and most modern poems (that is, poems from the Tang Dynasty and later, called ancient poems before the Tang Dynasty) also meet this requirement. However, there are still some typical works about phonology, such as Liu Zongyuan's five-character quatrain "Jiang Xue", the full text is in tune (short sound): there are no birds in the mountains, and there are no footprints in the thousand paths; A boat on the river, a fisherman wearing his webworm moth; Fishing alone is not afraid of snow and ice. There is no doubt that this poem is read with the rhyme ending of the ancient entering tone or with the rhyme of ie and ue in Mandarin today.
3, a rhyme to the end
In principle, there should be no rhyme changes in modern poetry, especially in poetry examination, poetry to be written and poetry with limited rhyme in science examination room. However, because the rhyming system used in scientific research does not fully conform to the spoken phonology of the Tang Dynasty, some vowels have been merged or separated, and it is more likely that some poets can't change their local accent and write poems with it, so there are still works that have been replaced by neighboring rhymes in their poems, such as Du Fu's Five Cases:
I live in my old grandson's house, simple and ancient style. When ploughing and chiseling, clothes are the same as the world.
Get up early at home and worry about your country and people. I wish you a good year. When it comes to the relationship between monarch and minister, there are many books.
Note: In sentences 2, 4 and 8, "Feng", "Tong" and "Zhong" are flat tones and "Dong" rhymes; In the sixth sentence, "feng" rhymes with "winter"
Writing poems every day is different from taking exams, so don't criticize the author, especially those who write poems with ancient rhymes in the future.
4. The first rhyme borrows rhyme
The rhyme of classical poetry can be mixed with the rhyme of neighboring rhymes, such as Dong Yi and Er Dong, Si Zhi and Wu Wei, which are called tongyun. However, in the rhyme of modern poetry, in principle, only words with the same rhyme can be strictly used. Even if there are few words in this rhyme (called narrow rhyme), it can't be mixed with words in other rhymes, otherwise it is called rhyme. But if the first sentence rhymes, you can borrow adjacent rhymes. Because the first sentence can be put or not, you can bend the rules.
Rhyme taboo
1, avoid rhyme
That is, the same rhyme word appears repeatedly in the rhyme of a poem, which is a big taboo.
2. Avoid synonyms.
For example, a poem uses "flower", "flower", "fragrance" and "fragrance" at the same time.
Step 3 avoid rhyming
Most ancient poems were written according to the official rhyme, and many words that we thought were homophones were included in different rhymes in the official rhyme, such as "winter" and "east". If you are juxtaposed in the same poem, it is rhyming. This is mainly due to the change of ancient and modern pronunciation, so it is unnecessary to emphasize this point today.